Have no idea how to do this-- Could someone show me how please. ​

Which linear equations have an infinite number of solutions? check all that apply.  (x  –  3/7)  =  2/7(3/2x  –  9/14)8(x  +  2)  =  5x  –  1412.3x  –  18  =  3(–6  +  4.1x)(6x  +  10)  =  7(x  –  2)4.2x  –  3.5  =  2.1 (5x  +  8)

10 ! in a race, nick is 50 feet in front of jay after ten seconds. how fast can nick run, if jay can run 20 feet per second?

Just tell me how to set up the equation.